feature #5157 commit content:
- fixing write error on very large file (more than 2Go)
- add a thumbnail extractor
feature #5157 add video thumbnail display
feature #5157 improve video thumbnail display (in order to distinguish photo and video)
fixing qtip tipurl display
feature #5157 fixing javascript interval problem
on feature #5157, fixing conflicts during merge of branch 'ebo-feature-5157' of https://github.com/ebonnet/Silverpeas-Components